Nanosized WC and WC-Co powders were synthesised by chemical vapor condensation(CVC) process using the pyrolysis of tungsten hexacarbonyl(W(CO)) and cobalt octacarbonyl(Co(CO)). The microstructural changes and phase evolution of the CVC powders during post heat-treatment were studied using the XRD, FE-SEM, TEM, and ICP-MS. CVC powders were consisted of the loosely agglomerated sub-stoichimetric WC and the long-chain Co nanopowders. The sub-stochiometric CVC WC and WC-Co powders were carburized using the mixture gas of CH-H in the temperature range of 730-85. Carbon content of CVC powder controlled by the gas phase carburization at 85 was well matched with the theoretical carbon sioichiometry of WC, 6.13 wt％. During the gas phase carburization, the particle size of WC increased from 20 nm to 40 nm and the long chain structure of Co powders disappeared.

A formation of aluminum hydroxide by hydrolysis reaction in the water has been studied by using nano aluminum powder fabricated by pulsed wire evaporation(PWE) method. The hydroxide type and morphology depending on temperature and pH were examined by structural analysis. The Boehmite(. or AIO(OH)) was predominantly formed in high temperature region over 4, while the Bayerite(. or ) below of hydrolysis temperature. The Boehmite formation was preferred to the Bayerite in acidic solution in the same hydrolysis temperature. The slowly formed Bayerite phase showed facet crystalline structure, while the fast formed Boehmite was fine fiber with a large aspect ratio of several nm in diameter and several hundred nm in length, and with much larger specific surface area(SSA) than that of Bayerite. The highest SSA was about /g.

In this study, various model composite latexes were synthesized using n-butyl acrylate and methyl methacrylate as comonomers by seeded multi-staged emulsion polymerization. Monodispersed model composite latex particles with size of 190 nm and polydispersity index of 1.05, which have various morphology including random copolymer particle, soft-core/hard-shell particle, hard-core/soft shell particle, and gradient-type copolymer particle, homopolymers particles were prepared. The designed morphology of model composite particles were confirmed.

We have conducted a V-band CCD surface photometry of 68 disk galaxies to analyze the bulge morphology of nearby spirals. We classify bulges into four types according to their ellipticities and the misalignments between the major axis of the bulge and those of the disk and the bar: spherical, oblate, pseudo triaxial, and triaxial. We found that one third of the bulges are triaxial and they are preponderant in barred galaxies. The presence of the triaxial bulges in a significant fraction of unbarred galaxies as well as in barred galaxies might support the secular evolution hypothesis which postulates that the bar driven mass inflow leads to the formation of triaxial bulges and the destruction of bars when sufficient mass is accumulated in the central regions.

본 연구는 고양이의 불임 해결을 위한 방안의 하나로써 체외수정란을 생산할 목적으로 난자의 형태, 보존 및 번식주기별 난자의 체외발생에 미치는 영향을 조사하였다. 1. 신선 난소로부터 회수한 난구세포부착 및 나화 난자를 각각 배양했을 때 GV 및 MI으로의 체외성숙율은 74.3%와 25.7%와 및 28.6%와 11.4%,로써 난구세포 부착 난자가 나화 난자의 비해 높은 체외성숙율을 나타냈다. 2. 휴지기, 난포기 및 황체기 단계로 구분하여 채취한 난구세포

Thin Ag films deposited onto substrates by DC magnetron sputtering and thereafter annealed ,it temperatures 100-50 are investigated by scanning tunneling and atomic forte microscopy. It is shown that the film surface topography and microstructure are considerably changed as a result of annealing. To provide a quantitative estimation of the surface topography changes of Ag films the surface fractal dimension was calculated. Elasticity and hardness of the films are studied by a nanoindentation technique. The films are found to have value of elastic modulus close to that of bulk silver while their hardness and yield stress are essentially higher.

Phase contents and elemental composition of ultradispersed powders obtained by the electrical explosion of tin-leadalloy powders are investigated. It is demonstrated that during the explosion and subsequent cooling, surface layers of powder particles are enriched in lead compared to the initial alloy. The thermal stability of powders oxidizing in air is also investigated.

정자의 동결보존을 위한 새로운 기술개발 목적은 동결과정에서 최소한의 손상으로, 응해 후 최대한 높은 활력도의 정자를 얻는 것이다 정자가 난자와 수정하기 위해서는 적당한 생존성과 운동성을 유지해야 하는데, 가장 일반적인 방법으로는 정자의 진진 운동성과 첨체의 정상 여부 및 형태 검사방법 등이 있다 본 연구는 사람 정액을 동결보존 할 때 semi-programmable freezer를 이용한 완만동결 방법과, 액체질소의 vapor를 이용한 급속동결 방법이

본 연구는 소형 개의 불임 해결과 체외수정란을 생산하기 위한 방안의 하나로써 난자의 형태, 번식주기, 배양시간 및 활성화 처리가 난포란의 체외성숙 및 체외발생에 미치는 영향을 조사하였다. 1. 신선, salt 및 4에 보존한 난소로부터 채취한 난구세포부착 난자와 나화 난자로 각각 체외수정시켰을 때 16세포기로의 발생율은 14.3%, 5.0% 및 7.5%, 2.8%, 5.7% 및 0.0%로써 난구세포 부착난자군의 체외발생율이 나화 난자군에 비해 높게 나타

토마토녹응애(개칭)에 대해 주사전자현미경 관찰, 국내 분포, 기주식물, 온도에 따른 발육상, 약제 방제법에 관하여 연구하였다. 토마토녹응애는 2쌍의 다리를 가진 길이 의 미소동물로 feathered claw는 4줄이었다. 피해증상으로, 피해엽은 적갈색으로 변하고 줄기에는 털이 없어지고 광택이 나거나 표면이 그물형으로 갈라지며, 새순은 시들거나 위축된다. 과일은 과경 부근에 그을음이나 녹이 긴 것 같이 되고, 그물형으로 갈라진다. 충남의 부여와 유성, 강원도 평창, 경북의 칠곡, 구룡포의 유리온실에서 발견되었으며, 한국에서 기주로는 메꽃, 까마중, 가지, 꽈리, 나팔꽃, 페투니아, 감자, 고추, 담배, 토마토 등이 확인되었다. 이 응애는 에서 발육이 가능하였고, 한 세대는 6-11일로 높은 온도일수록 발육기간이 짧아지는 경향이었으며, 암컷이 수컷보다 수명이 길었는데, 25-28에서 12일로 가장 수명이 길었다. 살비제 중에서 fenazaquin과 cypermethrin의 효과가 가장 좋았다.